Peel sweet potatoes and cut into 1” cubes. Bring a large pot of salted water to a boil. Drop in the sweet potato cubes, reduce heat, and simmer 12 to 15 minutes until tender enough to easily puncture with a fork. Drain sweet potatoes and mash until smooth. Let cool.
Line a muffin tin or mini muffin tin with paper liners, or spray with non-stick spray. Preheat oven to 350 F.
In a medium to large mixing bowl, beat butter and sugar until fluffy. Add egg and beat until incorporated. Beat in called sweet potatoes.
In a separate bowl combine flour, cornstarch, baking soda, baking powder, and salt. Mix about half of the dry ingredients into the sweet potato mix until almost incorporated.
Add in the vanilla and bourbon, and then beat in the remaining dry ingredients.
Fill each muffin cup 1/2 to 2/3 full. Bake for approximately 12 minutes, then remove from oven. Allow to cool completely.
Place Fluff in a heatproof bowl. Heat heavy cream in a small pot over medium-high heat, stirring occasionally until just boiling. Remove from heat, pour over Fluff and let sit a couple minutes for the hot cream to melt the Fluff. Stir until smooth.
Spoon the ganache over the tops of the cupcakes.
Maple Bourbon Marshmallow Frosting
Cream butter until fluffy. Gradually add in powdered sugar 1/2 cup at a time. Add bourbon and maple syrup. Fold in Fluff.
Frost cooled cupcakes. Top with a candied pecan or a bourbon soaked dried pineapple.